Dump grate for refuse burning furnaces



June l2, 1951 A. D. SIMPSON DUMP GRATE FOR REFUSE BURNING FURNACES 3Sheets-Sheet 2 Filed May 3, 1949 ||..Nv l |.ws ||s| o E N e w mw 7^ m5,m Mr r @n 3%# MM June 12, 1951 A D, 5|MP5ON 2,557,013

DUMP GRATE FOR REFUSE BURNING FURNACS Filed May 3, 1949 5 Sheets-Sheet 3Plq.

Patented June 12,Y 1951 DUMP GRATE FOR REFSE BURNING FURNACES Albert D.Simpson, Macon, Ga., assignor to The Hoft Company, Inc., Indianapolis,Ind., a corlporation Application May 3, 1949, Serial No. 91,039

4 Claims.

This invention relates to the construction of a dump grate for a refuseburning furnace of the type adapted for burning such fuels as bark,cotton seed, coconut hulls, sewer sludge, garbage, and like materialhaving a high moisture content. Reference is made to application forLetters Patent of Henry C. L. Miller, `Serial No. 67,802, filed December29, 1948, for Refuse Burning Furnace, and Letters Patents of Morris A.Hofft and Nick T. Puckett, No. 2,257,957, granted October 7, 1941, forFurnace Grate.

More particularly, the object of the invention is to provide such afurnace structure as disclosed in said patent and application forletters patent above mentioned with a Water cooled dump grate. Infurnaces of this 'character involving the burning -of refuse having ahigh content of moisture and foreign matter such as dirt, sand, and thelike, the dump grates are caused to rapidly deteriorate due to excessivetemperatures developed at this section of the furnace. Thus, the usualcast iron uncooled dump grates are apt to burn out necessitatingreplacements with the resultant requirement that the furnace beperiodically shut down.

It is, therefore, the object `of this invention to prolong the life ofthe dump grate by not only so constructing them as to permit of aircooling, but additionally causing them to be water cooled in order thatthey may withstand the eiects of prolonged high temperatures, while atthe same time providing for air passage and movement of fthe grates fromfuel supporting to fuel dumping positions.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims:

Fig. 1 is a horizontal section through a portion of a three cell furnacewith parts removed.

Fig. 2 is a section taken on the line 2-.-2 of Fig. 1 with theintermediate cell wall and other parts removed for showing therelationof the dump grates in adjacent cells, said grates being shown in fuelsupporting position by full lines and the outer cell grate being shownin fuel dumping position by dotted lines.

Fig. 3 is a plan view of the dump grate for one furnace cell with partsbroken away.

Fig. 4 is an enlarged section taken on the line 4-4 of Fig. 3.

Fig. 5 is a vertical section taken on the line 5--5 of Fig. 1,

In the drawings reference is made to the refuse vburning furnace of thegeneral type shown and and application for Letters Patent wherein fuelsare fed on to a downwardly sloping grate including, as shown herein, aseries of parallel spaced water cooled tubes itl terminating at theirlower end in a transverse header tube I I to provide for a flow ofcooling water throughout said grate surface. The grate surfaceintermediate the tubes I0 may comprise a series of grate bars of thestepladder type as shown inA said application for Letters Patent, or ofthe T apertured type as shown in said Letters Patent, the lower portionof the grate as illustrated therein including a series of pushers forfeeding the burning fuel from the lower portion of the grate on to thepump grate to which this lapplication is directed.

The pump grate is mounted over the ash pit I2 and normally extendssubstantially horizontally adjacent the lower portion of the grates andtubes I@ and transversely of the bridge walls i3.

As shown in Figs. 3 and 4, the dump grate for each cell of the furnaceconsists of a series of grate tubes I4 connectedat opposite ends to alongitudinally extending pivot tube I5 and an opposedlongitudinally-extending header tube I6, respectively. Opposite ends ofthe grate tubes I 4 are inV communication with the respective pivot tubeand header tube. Each of the grate tubes I4 has formed on opposite sidesthereof opposed grate lbars Il in the form of laterally extending finssubstantially coextensive with the space be tween the pivot tube andheader tube. Said grate tubes with their opposed grate bars are sospaced as to permit of an air passage between each pair of adjacentgrate bars.

Extending a substantial distance through the pivot tube from one endthereof there is provided ,a water pipe I8 having suitable connectionwith the cooling water source. Adjacent the same end of the pivot tubeit is provided with an outlet conduit I9. The water pipe I8 extendsthrough a rst baffle 29 and a second baflie ZI mounted in the pivottube, said baffles dividing the pivot tube into three sections. A singlebailleV 22 is provided substantially centrally of the header tube IS,dividing said header tube into two sections. Shown in Fig. 3, and notingthe direction of the arrows, the several bales in effect divide the dumpgrate into a series of water passages, the three grate tubes I4 farthestfrom the water inlet permitting flow of water from section Afof thepivot tube to section B of the header tube. y

The baille 2 I prevents back flow in the pivot tube so; that the onlyoutlet comprises the last said three grate tubes. As section B of theheader tube is blocked off by the baiiie 22, the water owing therein iscaused to iiow in the reverse direction through the next adjacent groupof grate tubes into section C of the pivot tube which is blocked oif bythe baiiies 20 and 2l. The flow of water is then permitted to returnfrom section C of the pivot tube to section D of the header tube on theother side of the baiile 22 from section B thereof. The ow is thenreversed to pass from section D of the header tube into section E of thepivot tube and be discharged therefrom through the outlet I9. Throughthis system of grate tubes and baiiles there is provided a circuitousflow of water through the entire dump grate from one end thereof to theother. The Water passage therethrough not only directly cools the gratetubes, but also cools through convection the grate bars formed thereon.

The dump grate of Fig. 3 is shown in Fig. 1 as mounted in the centercell of the three cell furnace. A dump grate similar thereto in allrespects is mounted in each of the outer cells. Thus, the dump gratestructure of the outer cells is provided with a pivot tube 15a ofprecisely the same arrangement as above described in respect to pivottube I5, including a water inlet pipe IBa, outlet I9a, and bafiles 20a,2Ia, and 22a. Each of the grate tubes Ida carry the laterally extendinggrate bars Ila. The pivot tubes of the grate bars of all three cellsextend throughout the full width thereof, the pivot tube Ia immediatelyunderlying the pivot tube I5. Thus, the center dump grate is supportedby the pivot tube I5, whereas the two outer cell dump grates aresupported by the pivot tube Ia. The respective pivot tubes are cradledin the bearings 23 and 24, the bearings 23 being mounted in the outerbridge Wall i3d, and the bearings 24 being mounted in the intermediatebridge walls I3.

The header tubes of all three dump grates are normally in axialalignment when the grates are in their upper fuel supporting position,the header I6 of the center dump grate being in axial alignment with theheaders IBa of the outer dump grates, as shown in Fig. 2; theintervening cell separating Wall being removed to show the relativepositions of the center and outer grates.

For dropping the dump grates from their approximately horizontal fuelsupporting position to a downwardly extending dumping position, eachdump grate is provided with a pair of downwardly extending arms 25,which are pivotally connected at their lower ends by the links 26 to thedump rods 2l extending toward the front end of the furnace, Said rods 21may be notched at 28 to hook over a latch bar 29 for latching the dumpgrates in raised fuel supporting position as shown in full lines in Fig.2. When the rods 21 are released to move inwardly to the position shownin dotted lines of Fig. 2, the dump grate is permitted to drop down toits dumping position about the axial center of its pivot tube header.

From the foregoing, it will be observed that through a simplearrangement of tubing a water cooled dump grate is provided not only forone grate cell, but for a plurality of adjacent grate cells, which maybe independently dumped while maintaining a constant now of watertherethrough, the iioW being substantially equalized throughout theentire length and area of the respective grates. The passage of thecooling iiuid through and about the tubular sections of each vgrate bothdirectly cools the tubular portion 4 I thereof and indirectly, throughconvection, cools the adjacent grate bars upon which the fuel issupported and through which air is permitted to pass.

The invention claimed is:

l. In a refuse burning furnace having a pluralityA of grate cells, adump grate for each cell comprising a pair of opposed parallel tubularheaders extending transversely of each cell, a series of equally spacedparallel tubular fuel supports connected with said headers incommunication therewith, one of said headers of each grate beingsupported upon said furnace in vertical offset relation With thecorresponding header of an adjacent grate, inletl and outlet connectionswith said last mentioned respective headers for introducing andexhausting a cooling fluid for circulation through said headers andconnecting fuel supporting tubes, and a manually operable dump controlmechanism operably connected with the opposed header of each grate forraising them to aligned fuel supporting position and lowering them tofuel dumping position about the axis of their respective offset headers.

2. In a refuse burning furnace having a plurality of grate cells, a dumpgrate for each cell comprising a pair oi opposed parallel tubularheaders extending transversely of each cell, a series of equally spacedparallel tubular fuel supports connected with said headers incommunication therewith, one of said headers of each grate beingsupported upon said furnace in Vertical offset relation with thecorresponding header of an adjacent grate, inlet and outlet connectionswith said last mentioned respective headers for introducing andexhausting a cooling iiuid for circulation through said headers andconnecting fuel supporting tubes, a manually operable dump controlmechanism operably connected with the opposed header of each grate forraising them to aligned fuel supporting position and lowering them tofuel dumping position about the axis of their respective oset headers,and bearing supports provided in said furnace for rotatably supportingsaid respective offset headers in vertically aligned adjacent position.

3. In a refuse burning furnace having a plurality of grate cells, a dumpgrate for each cell comprising a pair of opposed parallel tubularheaders extending transversely of each cell, a series of equally spacedparallel tubular fuel supports connected with said headers incommunication therewith, one of said headers of each grate beingsupported upon said furnace in vertical oset relation with thecorresponding header of an adjacent grate, inlet and outlet connectionswith said last mentioned respective headers for introducing andexhausting a cooling fluid for circulation through said headers andconnecting fuel supporting tubes, a manually operable dump controlmechanism cperably connected with the opposed header of each grate forraising them to aligned fuel supporting position and lowering them tofuel dumping position about the axis of their respective offset headers,and a series of baffles in said headers so arranged therein relative tosaid fuel supporting conduits as to direct the flow of iiuid for evendistribution therethrough.

4. In a refuse burning furnace having a plurality of grate cells, a dumpgrate for each cell comprising a pair of opposed parallel tubularheaders extending transversely of each cell, a series of equally spacedparallel tubular fuel supports connected with said headers incommunication therewith, one of said headers of each 5 grate beingsupported upon said furnace in vertical offset relation with thecorresponding header of an adjacent grate, inlet and outlet connectionswith said last mentioned respective headers for introducing andexhausting a cooling fluid for circulation through said headers andconnecting fuel supporting tubes, a manually operable dump controlmechanism operably connected with the opposed header of each grate forraising them to aligned fuel supporting position and lowering them tofuel dumping position about the axis of their respective offset headers,and laterally extending grate bars on each of said tubular fuel supportsextending laterally in the plane thereof toward and in spaced relationto adjacent grate bars.

ALFRED D. SIMPSON.

REFERENCES CITED The following references are of record in the me ofthis patent:

Number Number 6 UNITED STATES PATENTS Name Date Nevins Jan. 28, 1866Seddon Sept. 23, 1873 Shackelford Sept. 23, 1884 Pollock Apr. 4, 1893Thurell Feb. 5, 1901 Sawyer June 10, 1902 Johnson Dec. 27, 1904 SchmidtMar. 30, 1909 MacKay Aug. 24, 1915 Nye Feb. 1, 1916 Barnett Feb. 15,1916 Frechette June 17, 1924 Von Mattekovich June 2, 1936 Hofft et al.Nov. 7, 1941 FOREIGN PATENTS Country Date Austria Dec. 15, 1900

